One vertex per element, one color per generator, with an edge from x to x·s.
(1,2)(3,7)(4,6)(5,8)(10,12)(11,17)(16,20)(19,21)(25,26,30,29)(27,31,33,35)(28,32,36,37)(34,38,39,40)(1,2,4,6)(3,5,8,7)(9,10,14,12)(11,18,17,15)(13,16,22,20)(19,24,21,23)(27,33)(31,35)(34,39)(38,40)(1,2)(3,5)(4,6)(7,8)(9,10,14,12)(11,15,17,18)(13,16,22,20)(19,23,21,24)(25,27,30,33)(26,31,29,35)(28,34,36,39)(32,38,37,40)(1,3,4,8)(2,5,6,7)(9,11,14,17)(10,15,12,18)(13,21,22,19)(16,24,20,23)(25,28)(26,32)(27,34)(29,37)(30,36)(31,38)(33,39)(35,40)(9,12,14,10)(11,18,17,15)(13,20,22,16)(19,24,21,23)(9,13,14,22)(10,16,12,20)(11,19,17,21)(15,23,18,24)(25,29,30,26)(27,35,33,31)(28,32,36,37)(34,38,39,40)A Cayley diagram is a choice, not a fact about the group. Another drawing of this group — in a book, or on a different generating set — may look nothing like this one.